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        "%matplotlib inline"
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      "source": [
        "\n# Nearest Centroid Classification\n\n\nSample usage of Nearest Centroid classification.\nIt will plot the decision boundaries for each class.\n\n"
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      "source": [
        "print(__doc__)\n\nimport numpy as np\nimport matplotlib.pyplot as plt\nfrom matplotlib.colors import ListedColormap\nfrom sklearn import datasets\nfrom sklearn.neighbors import NearestCentroid\n\nn_neighbors = 15\n\n# import some data to play with\niris = datasets.load_iris()\n# we only take the first two features. We could avoid this ugly\n# slicing by using a two-dim dataset\nX = iris.data[:, :2]\ny = iris.target\n\nh = .02  # step size in the mesh\n\n# Create color maps\ncmap_light = ListedColormap(['orange', 'cyan', 'cornflowerblue'])\ncmap_bold = ListedColormap(['darkorange', 'c', 'darkblue'])\n\nfor shrinkage in [None, .2]:\n    # we create an instance of Neighbours Classifier and fit the data.\n    clf = NearestCentroid(shrink_threshold=shrinkage)\n    clf.fit(X, y)\n    y_pred = clf.predict(X)\n    print(shrinkage, np.mean(y == y_pred))\n    # Plot the decision boundary. For that, we will assign a color to each\n    # point in the mesh [x_min, x_max]x[y_min, y_max].\n    x_min, x_max = X[:, 0].min() - 1, X[:, 0].max() + 1\n    y_min, y_max = X[:, 1].min() - 1, X[:, 1].max() + 1\n    xx, yy = np.meshgrid(np.arange(x_min, x_max, h),\n                         np.arange(y_min, y_max, h))\n    Z = clf.predict(np.c_[xx.ravel(), yy.ravel()])\n\n    # Put the result into a color plot\n    Z = Z.reshape(xx.shape)\n    plt.figure()\n    plt.pcolormesh(xx, yy, Z, cmap=cmap_light)\n\n    # Plot also the training points\n    plt.scatter(X[:, 0], X[:, 1], c=y, cmap=cmap_bold,\n                edgecolor='k', s=20)\n    plt.title(\"3-Class classification (shrink_threshold=%r)\"\n              % shrinkage)\n    plt.axis('tight')\n\nplt.show()"
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